Benzo[a]pyren-8-ol-d11 is labelled Benzo[a]pyren-8-ol (B205835) which is a metabolite of Benzopyrene (B205800) with antiestrogenic activity. Benzo[a]pyren-8-ol is also a useful synthetic intermediate in the synthesis of Benzo[a]pyrene-7,8-diol (B205840).